Although most previous epidemiological surveys of mental disorders in adults
neglected to track such impulse control disorders as attention-deficit/
hyperactivity disorder, intermittent explosive disorder (IED), conduct disorder
(CD) and oppositional defiant disorder (ODD), the recently completed National Comorbidity Survey Replication (NCS-R) found that their
combined lifetime prevalence is higher than that for either mood disorders or
substance use disorders.

"Surprisingly, impulse control disorders ... were found in 8.9% (12-month
prevalence) and 24.8% (lifetime prevalence) of the population with a greater
proportion at the serious level than either anxiety or substance disorders,"
noted a commentary accompanying publication of four papers on the NCS-R in the Archives of General Psychiatry (Insel and Fenton, 2005).

For comparison, the lifetime prevalence of mood disorders was 20.8% and of
substance use disorders was 14.6%. Only the lifetime prevalence of anxiety disorders
at 28.8% exceeded that of impulse control disorders (Kessler et al., 2005a).

The $20 million NCS-R was a collaborative project between Harvard University
Medical School,
the University of
Michigan Institute for
Social Research and the National Institute of Mental Health Intramural Research
Program. It is a nationally representative survey of 9,282 English-speaking
household residents age 18 and older in the coterminous United States.

Ronald C. Kessler, Ph.D., professor of health care policy at Harvard Medical
School and designer of the NCS-R, pointed out that all major psychiatric
epidemiological studies in the past, particularly the Epidemiologic Catchment Area (ECA) study in the 1980s (Robins and Regier, 1991) and the National Comorbidity
Survey (NCS) in the 1990s (Kessler et al., 1994), have essentially focused on
anxiety and depression.

"Over the last decade, we have come to recognize that violence is not on
anybody's radar screen, so I thought that when we did this survey, we really
needed to talk about hostility, not just anxiety and sadness," Kessler told Psychiatric Times in an exclusive
interview. "People who study moods think of it as a triumvirate--anxiety,
hostility and depression, but hostility seems to have fallen off the radar
screen in psychiatric epidemiology, so that was the simple-minded notion when I
first started approaching this issue."